Mrs. Sonia buys Rs. 249.00 worth of candies for the children of a school. For each girl she gets a strawberry flavoured candy priced at Rs. 3.30 per candy; each boy receives a chocolate flavoured candy priced at Rs. 2.90 per candy. How many candies of each type did she buy?

Let the number of strawberry flavoured candy = x and the number of chocolate flavoured candy = y
Thus, as given in the question:-
3.3x + 2.9y = 249
Using options,
Option A = 3.3*21 + 2.9*57 = 69.3+165.3 = 234.6 Rs $$\neq$$ 249
Hence, option A cannot be the answer.
Option B = 3.3*57 + 2.9*21 = 188.1+60.9 = 249
Thus, option B can be the answer.
Option C = 3.3*37 + 2.9*57 = 241.8 $$\neq$$ 249
Hence, option C cannot be the answer.
Option D = 3.3*27 + 2.9*51 = 237 $$\neq$$ 249
Thus, option D cannot be the answer.

Hence, option B is the correct answer.